The invention relates to an apparatus and to a method for manually setting a parameter of a lens of a television, video or studio camera. In particular, the invention relates to an apparatus and a method for manually setting the distance between the camera and an object, which is to be photographed. Especially, it shall be possible to set the distance herewith for electronic camera with auto focusing.
The German utility patent 20308400 discloses a device, which has a holder, which can be connected with the camera, for a hand wheel, which can be rotated about an axis of rotation, and a gear mechanism, which is brought into engagement with an adjusting hand wheel in a corresponding wheel at the lens for setting the parameter and especially the distance. Between the hand wheel and the adjusting hand wheel, a wheel drive is provided, for example with gear wheels, so that this apparatus works absolutely without clearance.
For some photographing situations, it is necessary to switch the lens frequently between two distance values, for example, when photographing a discussion between two persons, for which the cameraman must adjust the lens for each new alignment of the camera, in order to achieve the desired sharpness or an intentional fuzziness.
This manual setting of the distance is particularly critical for modern electronic television, video or studio cameras with auto focusing. They have the advantage that a cameraman no longer has to set the desired distance between the camera and the object to be photographed manually and that, instead, this is done automatically, for example, by a contrast measurement or a phase comparison. In many cases, especially when the object to be photographed is not in the region of the field of view of the lens, which is the measuring region for the auto focusing, it is desirable to be able to set this parameter also manually, in order to set the sharpness and fuzziness selectively.
However, the known apparatus of the aforementioned DE 20308400, in conjunction with electronic cameras, cannot be taken over in this form for setting the distance manually. If, for example, a lens, aimed with the camera, is focused by the automatic focusing feature, the distance ring of the lens can be rotated manually, without changing the focusing thereby. This is the case especially when the setting limits of infinity and close up are reached, because a manual adjustment of the distance does not lead to a change in the distance setting in every case, but only to a loss of the reference point for the distance setting, so that the cameraman must focus the lens once again.
This is extremely tedious for a cameraman, for example, when two parties to an interview are photographed at different distances; each time the lens has to be focused or the desired fuzziness set once again.